When prices arc upward at ever-increasing speed, they form a parabolic curve, which should cause us to feel ever-increasing caution. With parabolic moves we never know when the final top will arrive because of the frenzy of buying driving the move, but we know that vertical moves cannot be sustained, and ultimately we can expect that the parabolic will collapse, with prices falling as quickly as they advanced. Let’s look at a few charts that caught my eye.